Ai Ohto, a 14-year-old girl with striking heterochromia—a golden-amber left eye and a deep blue right eye typically hidden under her bangs—withdraws from the world after enduring bullying and the devastating suicide of her sole friend, Koito Nagase. Consumed by guilt over Koito’s death, initially attributed to bullying, Ai fixates on reviving her through a cryptic system involving "Wonder Eggs" dispensed by a gachapon machine. Each egg transports her to a surreal dreamscape where she battles monstrous "Seeno Evils" and "Wonder Killers," manifestations of trauma tied to girls’ suicides. Armed with a multicolored pen morphing into a spiked mace, Ai improvises weapons from ribbons, penlights, or prayer beads, aided by Leon, a chameleon-like companion hatched from a pomander gifted by enigmatic arbiters Acca and Ura-Acca.

Allied with Neiru, Rika, and Momoe—each wrestling with personal demons—Ai evolves from a timid recluse into a resolute protector, driven by hopes of reuniting with Koito. Her journey intertwines confronting guilt, shielding others in dream realms, and navigating real-world complexities, including her mother’s engagement to Shūichirō Sawaki, Koito’s former teacher. A haunting parallel reality reveals an alternate Ai who, lacking Koito’s influence, succumbed to bullying and drowned herself. The original Ai encounters this fragile double during a mission, witnessing her sacrificial demise to vanquish a trauma-born entity.

Ai’s relentless efforts yield a partial resurrection: Koito returns devoid of shared memories, yet Ai persists, redirecting her mission to revive Neiru after her apparent death. Her bedroom, adorned with calla lilies symbolizing rebirth and morning glories reflecting transient bonds, shifts from a solitary sanctuary to a communal haven for her friends, mirroring her emotional thaw. The narrative weaves trauma, resilience, and fractured healing against unresolved mysteries—the arbiters’ motives, the system’s origins—leaving Ai’s path open amid lingering shadows of loss and connection.